The use of data compression or encoding schemes to reduce the size of files for backup or file transmission is well known in the art. Many types of data and files are compressed, including images in the well known GIF and JPEG formats (though including many others), video in the MPEG format, sound in MP3 and other formats, as well as standard archive formats, such as SIT, ZIP, GZIP, and so forth. Furthermore, many types of files have compressed images embedded inside, e.g., PDF files, WORD documents, and the like.
Files and data streams that have been compressed using sub-optimal techniques now comprises a major part of existing data, both for storage and transmission. (As used herein “file” and “data stream” are used interchangeably to denominate an identified set of data elements which may exist in several forms, including in a discrete form, or combined or stored with other files, or embedded in another file as a file or as an object, or as a file containing other files, or as a data stream of determinate or indeterminate size, including information transmitted over a data channel.) Compressed files are frequently large, and despite the considerable advances made in mass-storage density, computer processor speeds, and telecommunication system performance, compression techniques do not yet satisfactorily solve the space and transmission bandwidth problems. Developers of compression technology are now hard pressed to keep pace with the rapid growth of multimedia web-based applications which utilize enormous amounts of data. It would be advantageous, therefore, to provide improved methods to compress digital image files. Moreover, it is desirable that such improved compression be lossless.
Accordingly, the present invention provides a digital image compression system and method that losslessly compresses digital images.